My name is Mason Porter. I am a Professor in the Department of Mathematics at UCLA. Previously I was Professor of Nonlinear and Complex Systems in the Mathematical Institute at University of Oxford. I was also a Tutorial Fellow of Somerville College.

After 586 (est, including 83 I played in) straight losses in SCIAC, dating back to 1988:
Caltech Beavers DEFEAT Pomona-Pitzer 4-3 on WALKOFF single.

No one on this team had yet been born the last time Caltech registered a SCIAC win in baseball.

1988... such a magical year for baseball...

Update: And here are some details: Caltech baseball has just won its first SCIAC game since 1988! Trailing 3-2 headed to the 9th inning, the Beavers got a two-out single from David Watson, who was replaced on the base paths by Schaffer Reed. Senior Kai Kirk then smacked a double to left center to tie the game, bringing freshman Alex Corado came up to bat. The rookie got ahead 3-0 before facing a full count and slashed a single to left field to plate the historic walk-off run.

Update: Also take a look at the video and the ensuing victory celebration.

Update (4/01/17): This is not an April Fool's Day joke. (I know it sounds like one.)

Thursday, March 30, 2017

Here's an April Fool's Day paper on the arXiv. The title of the paper is: A Neural Networks Approach to Predicting How Things Might Have Turned Out Had I Mustered the Nerve to Ask Barry Cottonfield to the Junior Prom Back in 1997

(The arXiv doesn't have 1 April as a mailing day this year, so we get it early.)

The last sentence of the abstract is amusing: "Over-training is also discussed, although the linear algebra teacher assures us that in Barry’s case this is not possible."

As things catch my eye, I will post links to more April Fool's Day shenanigans.

Here are various past posts related to April Fool's Day (and a couple of other posts that show up in the search but aren't particularly related).

Update: Here is another joke arXiv paper. It is called: Schrodinger's Cat and World History: The Many Worlds Interpretation of Alternative Facts

Update:This article seems to purposely be dated April 1st, but it has a rather different flavor from the other two.

Update: According to an April 1st article in The Guardian, former British chancellor (more formally, "Chancellor of the Exchequer") George Osborne has become a fashion designer. (Tip of the cap to Dominic Vella.)

Update (4/01/17) Here is a screenshot of my April Fool's Day prank of 2006, for which I was able to convince a member of Caltech's public-relations department to post my article (actual fake news, which of course is an April 1st tradition) on the Caltech web page and include a link to it in an e-mail circular.

Update (4/01/17):Cherwell, a student publication from University of Oxford, published an interesting story about possible cancellation of the Cancer Research UK Boat Races. Here is another one from Cherwell.

Update (4/08/17): Well, the Reddit prank appears to have resulted in a rather interesting example of self-organization (and of astounding art, with some "This is why we can't have nice things." thrown in). (Tip of the cap to Kevin Hickerson, Maria Satterwhite, and others.)

Abstract: Numerous centrality measures have been developed to quantify the importances of nodes in time-independent networks, and many of them can be expressed as the leading eigenvector of some matrix. With the increasing availability of network data that changes in time, it is important to extend such eigenvector-based centrality measures to time-dependent networks. In this paper, we introduce a principled generalization of network centrality measures that is valid for any eigenvector-based centrality. We consider a temporal network with N nodes as a sequence of T layers that describe the network during diff erent time windows, and we couple centrality matrices for the layers into a supracentrality matrix of size NT x NT whose dominant eigenvector gives the centrality of each node i at each time t. We refer to this eigenvector and its components as a joint centrality, as it reflects the importances of both the node i and the time layer t. We also introduce the concepts of marginal and conditional centralities, which facilitate the study of centrality trajectories over time. We find that the strength of coupling between layers is important for determining multiscale properties of centrality, such as localization phenomena and the time scale of centrality changes. In the strong-coupling regime, we derive expressions for time-averaged centralities, which are given by the zeroth-order terms of a singular perturbation expansion. We also study first-order terms to obtain fi rst-order-mover scores, which concisely describe the magnitude of the nodes' centrality changes over time. As examples, we apply our method to three empirical temporal networks: the United States Ph.D. exchange in mathematics, costarring relationships among top-billed actors during the Golden Age of Hollywood, and citations of decisions from the United States Supreme Court.

Abstract: Although networks provide a powerful approach to study a large variety of ecological systems, their formulation does not typically account for multiple interaction types, interactions that vary in space and time, and interconnected systems such as networks of networks. The emergent field of ‘multilayer networks’ provides a natural framework for extending analyses of ecological systems to include such multiple layers of complexity, as it specifically allows one to differentiate and model 'intralayer' and 'interlayer' connectivity. The framework provides a set of concepts and tools that can be adapted and applied to ecology, facilitating research on high-dimensional, heterogeneous systems in nature. Here, we formally define ecological multilayer networks based on a review of previous, related approaches; illustrate their application and potential with analyses of existing data; and discuss limitations, challenges, and future applications. The integration of multilayer network theory into ecology offers largely untapped potential to investigate ecological complexity and provide new theoretical and empirical insights into the architecture and dynamics of ecological systems.

Update: Terry Tao has written a short blog post about the prize. Among other things (and I hadn't caught this), note the following text from Tao: Daubechies also made extremely important contributions to the theory of wavelets, but my understanding is that due to a conflict of interest arising from Daubechies’ presidency of the International Mathematical Union (which nominates members of the Abel prize committee) from 2011 to 2014, she was not eligible for the prize this year, and so I do not think this prize should be necessarily construed as a judgement on the relative contributions of Meyer and Daubechies to this field.

This article on The Daily Dot suggests adding the phrase "and then the murders began" to the first sentence of the book that one is reading. This can change the tone of the book in very amusing ways.

As a twist on this, I decided to look at the first sentence of the preface of one of my books. This yields the following sentence: "Traditionally, much of the study of networks has focused on structural features, and then the murders began."

Unfortunately, the tense of the sentence hurts things, so I am going to change one letter ("s" to "d" in the word "has") to produce the following sentence: "Traditionally, much of the study of networks had focused on structural features, and then the murders began."

Wednesday, March 08, 2017

Just as a reminder, you should definitely be reading the @RoguePOTUSStaff Twitter feed, which appears to be legit. It is also hilarious and gives fascinating insights as to what is going on in The White House days. For example, consider the following gem from today:

Spicer: "I wish he'd have an affair. That'd be better than defending the stupid s*** he says in Twitter."

Tuesday, March 07, 2017

It should say "specializes" (present tense), by the way, as Karin is still research-active, even though she's retired. In fact, no doubt, she is now more active in her research, as that is how it often works.

As I write this, the tumblr has gotten up to 'M' so far, and there are many great mathematicians profiled (including, thankfully, people besides the same ones that often show up over and over again in such lists).

About Me

I am a Professor in the Department of Mathematics at UCLA.
Previously, I was Professor of Nonlinear and Complex Systems in the Mathematical Institute at University of Oxford. I was also a Tutorial Fellow in Somerville College. I am also a die-hard fan of the Los Angeles Dodgers. See my website for more information about me. You can also find me on Facebook and Twitter (@masonporter), though I'm much easier to stalk by other means. If you want power law or Zachary Karate Club swag, take a look at my Power Law Shop. I am also involved with the Legends of Caltech movie and co-edited Legends of Caltech III.